GB2201588A

GB2201588A - Adjustable wheelchair

Info

Publication number: GB2201588A
Application number: GB08729785A
Authority: GB
Inventors: Dermot Maynes
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-12-22
Filing date: 1987-12-22
Publication date: 1988-09-07
Anticipated expiration: 2007-12-22
Also published as: GB2201588B; GB8729785D0

Abstract

A wheelchair has a frame (10) comprising an upright back support (16) and a chassis (18) with four ground-engaging wheels (20) arranged two at the front and two at the back thereof. The frame (10) carries a seating portion (12) and a back rest portion (14) which are hinged together (8). The chassis (18) is length-adjustable to increase or decrease the length of the wheelbase, and the back rest portion (14) is in sliding relation with the upright back support (16) whereby on extension of the wheelbase, the back rest portion (14) adopts a reclined attitude. The seating portion (12) is height-adjustable relative to the frame. With full increase in height of the seating portion (12) and full increase in the wheelbase, the back rest portion (14) adopts a near coplanar attitude relative to the seating portion. <IMAGE>

Description

WHEELCfIAIRS.

This invention relates to wheelchairs.

A user of an existing wheelchair has problems in transferring from a bed to the wheelchair and vice versa. This operation normally requires the assistance of at least one other party to manhandle the user from one flu ton to the other. Depending on the weight of the user, this task can be a problem in that it can be extremely onerous on the or each other party. Due to this problem, many patients who could usefully, beneficially and therapeutically be accommodated in a wheelchair are not given assistance and hence become bedbound.

An object of the present invention is to mitigate this problem.

Accordingly, the present invention is a wheelchair having a frame carrying a seating portion and a back rest portion, the frame having an upright back support and = chassis with four ground-engaging wheels arranged two at the front and two at the back, the chassis being length-adjustable to increase or decrease the length of the wheelbase, the back rest portion being in sliding relation with the upright back support of the frame whereby on extension of the wheelbase, the back rest portion adopts a reclined attitude.

Preferably, the seating portion is height adjustable relative to the frame. With full increase in height of the seating portion and full increase in the wheelbase, the back rest portion adopts a near co-planar attitude relative to the seating portion. The height off the ground of the seating portion at full increase of height is preferably substantially that of a bed, strether trolley or the like whereby to facilitate easy transfer from one to the other.

Preferably also, the seating portion and the back rest portion are hinged together.

Preferably further, the length-adjustment of the wheelbase is governed by a first piston and cylinder arrangement. The height-adjustment of the seating portion is preferably governed by a second piston and cylinder arrangement. Power means are provided to operate the piston and cylinder arrangements. Controls for actuating said power means are preferably positioned on or near to one of the arm rests.

The seating portion may preferably have removable arm rests which fit into mounting means provided on each lateral side of the seating portion. A tray may preferably be provided to be secured to one or both arm rests.

Foot rests may preferably be provided for heightadjustment on leg support(s) carried on the seating porticn.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which: Fig. 1 is a side elevational view of a wheelchair according to the present invention with the wheelchair shown in a normal wheelchair state, Fig. 2 is a side elevational view of a wheelchair shown in an extended state; Figs. 3 and 4 are side views of a detail of a modification shown respectively in a lower and an upper position; and Fig. 5 is a side view of an enlarged detail of a modified arm rest.

Referring to Figs. 1 and 2 of the drawings, a wheelchair has a frame 10 carrying a seating portion 12 and a back rest portion 14 which are hinged together at 8. The frame 10 has an upright back support 16 and a rectangular chassis 18 with four ground-engaging wheels 20 arranged two small wheels at the front and two large wheels at the back. The chassis 18 has two lateral side members 18A each telescopically length-adjustable to increase or decrease the length of the wheelbase. The length-adjustment of the wheelbase is governed by a first piston and cylinder arrangement 26. The upright back support 16 is two uprights 22 stayed by a bar handle 24, each upright having a wheel 42 carried on a inwardly laterally-extending stub shaft (not shown). The back rest portion 14 is a support 14A faced with a padded cushion 14B.The back rest portion 14 is in sliding relation with the upright back 16 of the frame 10, each lateral side of the support 14A being of channel section with the channels facing outwardly. The wheels 42 track a respective channel of the support 14A whereby on extension of the wheelbase, the back rest porti 14 adopts a reclined attitude.

The seating portion 12 has a rectangular sub-frame 12A supporting a padded seat 12B and is height-adjustable relative to the frame 10. As can be seen in the drawings, the sub-frame 12A is connected through linkages 36 with the chassis 18. The heightadjustment of the seating portion is governed by a second piston and cylinder arrangement 28.

The seating portion 12 has removable arm rests 32 provided on each lateral side of the sub-frame 12A of the seating portion 12. The arm rests 32 each has an inverted 'U' member with a padded cushion secured to the top the web with the limbs of the 'U' fitting into mounting means, namely two spaced, upright tubular sockets 34. Front extensions 58( Fig. 5) may be provided in the arm rests 32 to extend forwardly from or retract into the arm rests 32. Such extensions 58 are to assist a user to raise or lower himself/herself relative to the seating portion 12 A tray (not shown) can be provided to be secured to one or both arm rests 32.

Power-means ( not shown ), namely a hand primed pump or more sophisticatedly a battery operated hydraulic power pack, is mounted on the chassis 18 under the seating portion 12 and is provided connected to the piston and cylinder arrangements to operate same.

Controls (indicated generally at 30 in Fig.2) for actuating said power means are positioned on or near to one of the arm rests 32.

Brakes (not shown) are provided to secure the wheelchair on a surface when stationary and are particularly for use when the user is to raise or lower himself/herself from or into the wheelchair.

A foot rest 38 is provided for height-adjustment on two transversely spaced leg supports 40 carried on the sub-frame 12A of the seating portion. The supports 40 are channelled and a slide 44, extending out from an upright 46 rooted to the chassis 18, tracks same.

Additional individual removable leg supports 60 ( Figs.2,3) can be provided for fitment to the leg supports 40 at the top thereof to extend horizontally and parallel to the seat 12B. These additional leg supports would normally be fitted by a helper, and are of use when the back rest portion is reclined, or when the user has, for example a leg or legs in plaster.

With full increase in height of the seating portion 12 and full increase in the wheelbase, the back rest portion 14 adopts a near co-planar attitude relative to the seating portion as shown in Fig.2. The height off the ground of the seating portion 12 at full increase of height is substantially that of a bed, strether trolley or the like whereby to facilitate easy transfer from one to the other.

Tn use, the wheelchair can be wheeled up to the side of a bed, the wheelbase extended and the seating portion heightened, the adjacent arm rest 32 removed, and the wheelchair pushed against the bed. With the bedclothes removed, the patient can be transferred from the bed to the wheelchair. The patient can then lower the seating portion 12, and incline the back rest portion 14. The patient can then be pushed or move the wheelchair to a suitable location. There he/she can recline the back rest portion 14 as required. To return the patient to bed, the reverse sequence of steps are followed.

In a first modification as shown in Figs. 3 and 4, the foot rest is carried at each lateral side by two links 50 to arcuately move the links 50 between a lower and an upper position. The links 50 are biased by spring 52 to the lower position and are movable by extension and retraction of a third piston and cylinder arrangement 54. The cylinder of the arrangement 54 is pivotally connected to the upright 46. The spring 52 is anchored between the sub-frame 12A and the forward of the two links 50.

Figs. 3 and 4 also show a lift mechanism provided at the front of the seating portion. This lift mechanism is a small piston and cylinder arrangement and serves when extended to raise the front of the seating portion to assist in preventing a person using the wheelchair from slipping off accidentally.

The arm rests 32 may, in a modification, have their limbs fitted with inwardly-facing rachets and a handle operated cog wheel is provided to raise or lower the individual arm rest.

Variations and modifications can be made without departing from the scope of the invention.

Claims

CLAIMS:

1. A wheelchair having a frame carrying a seating portion and a back rest portion, the frame having an upright back support and a chassis with four groundengaging wheels arranged two at the front and two at the back, the chassis being length-adjustable to increase or decrease the length of the wheelbase, the back rest portion being in sliding relation with the upright back of the frame whereby on extension of the wheelbase, the back rest portion adopts a reclined attitude.

2. A wheelchair as claimed in Claim 1, wherein the seating portion is height-adjustable relative to the frame.

3. A wheelchair as claimed in Claim 2, wherein with full increase in height of the seating portion and full increase in the wheelbase, the back rest portion adopts a near co-planar attitude relative to the seating portion.

4. A wheelchair as claimed in Claim 2 or 3, wherein the height off the ground of the seating portion at full increase of height is substantially that of a bed, strether trolley or the like whereby to facilitate easy transfer from one to the other.

5. A wheelchair as claimed in Claim 1, 2, 3 or 4, wherein the seating portion and the back rest portion are hinged together.

6. A wheelchair as claimed in anyone of the preceding Claims, wherein the length-adjustment of the wheelbase is governed by a first piston and cylinder arrangement.

7. A wheelchair as claimed in anyone of Claims 2, 3, 4, 5 or 6, wherein the height-adjustment of the seating portion is governed by a second piston and cylinder arrangement.

8. A wheelchair as claimed in Claim 6 or 7, wherein power means are provided to operate each piston and cylinder arrangement.

9. A wheelchair as claimed in Claim 8, wherein controls for actuating the power means are positioned on or near to one of the arm rests.

10. A wheelchair as claimed in any one of the preceding Claims, wherein the seating portion has removable arm rests which fit into mounting means provided on each lateral side of the seating portion.

11. A wheelchair as claimed in Claim 10, wherein a tray is provided to be secured to one or both arm rests.

12. A wheelchair as claimed in any one of the preceding Claims, wherein a foot rest is provided for heightadjustment on leg support(s) carried on the seating portion.

13. A wheelchair as claimed in Claim 12, wherein indiv.i.iilal removable leg supports are provided for fitment in a horizontal attitude to the top of the leg supports.

14. A wheelchair as claimed in Claim 12, wherein the foot rest is carried at each lateral side by two links to arcuately move the links between a lower and an upper position.

15. A wheelchair as claimed in Claim 14, wherein the links are biased to the lower position and are movable by extension and retraction of a third piston and cylinder arrangement.

16. A wheelchair substantially as hereinbefore described with reference to the accompanying drawings.